| 摘要 |
A guidewire arranged to be transported through the vascular system composed of a helically wound spring attached to a second helically wound distal spring of a more radiopaque material by winding the two segments together over the core, but without attachment to the core thus allowing the core to freely move within the spring thus providing for tip flexibility and movement. The helically wound springs may be tapered from the proximal to distal segment or straight, and a length of tubing is attached to the proximal end of the proximal spring segment with a ground distal tube segment to make for a flush fitting to the coil and a smooth continuous outside diameter of the guide wire. A tapered core wire is moveably disposed in the tubing and springs with a swaged distal segment to allow for forming and to increase flexibility in one plane without sacrificing torque. The core wire is attached to the end of the distal spring segment providing torque to the entire spring and movement of the core allows for varying the stiffness and support of the spring segment and for straightening the distal spring segment. Alternatively a restraining wire may be attached to the inner surface of and extending to the tip of the spring segment from the distal tube segment to allow bending the distal spring segment by advancing the core. The invention also includes a means for extending the length of said guidewires.
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